Regulator for alternating-current motors.



No. 839,958. PATENTED JAN. 1, 1907.

O. RENSHAW.

REGULATOR FOR ALTBRNATING CURRENT MOTORS. APPLIOATION FILED FEB. e, 1905.

3 SHEETS-SHEET 1.

W l 4 I 3 WITNESSES: INVENTOR v I ATTORNEY 0. RENSHAW. REGULATOR FOR ALTERNATING CURRENT MOTORS.

APPLICATION FILED FEB. 6, 1905.

w INVENTO Mg Y 2 I E v a zz 2 P-ATENTED JAN. 1, 1907.

3 SHEETS-SHEET 2.

No. 839,958. P'ATENTBD JAN. 1, 1907.

.G- RENSHAW. REGULATOR FOR ALTERNATING CURRENT. MOTORS.

APPLICATION FILED FEB.6. 1905.

s SHEETS-SHEET a.

" WITNESSES:

' l NV 'OR following ,is a specification.

"-eration may be secured.

UNITED srA rnS i i-Thur CLARENCE RENSHAVV, OF WILKINSBURG, PENNSYLVANIA. ASEIG I03 "3.)

WESTINGHOUSE ELECTRIC & MANUFACTURING .PORATlUN OF PENNSYLVANIA.

eorrraur, A (JOB BEGtJLATOF-i FOR ALTERNATING-CURRENT MGTQRSI Specification of Letters Patent.

Patented Jan. 1, 1907.

Applic i n fi February 6, 1905. Serial No. 244,481.

To all whom it may concern:

Be it known that I, CLARENCE RENsHAw, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny.

and State of Pennsylvania, have invented a new anduse'rul Improvement in Regulators for Alternating-Current Motors, of which the My invention relates to alternatingecur rent motors of the commutator type of construction; and its object is to provide improved means for supplying energy to such motors from multiphase sources, whereby the proper phase relations oi-the currents trav-; ersing the armature andfield-magnet wind ingsfor the most efficient and economical op- In general'rilotors of the commutator type.

. of. construction it properly designed may be.

operated efiiciently by means of alternating currents, provided the currents in the armature andfield-magnet windings reverse simultaneously, or nearlyso. If the armaturewinding and the field-magnet winding of a motor of the commutator type having laminated magnetic circuits are supplied, respectively, with alternating:mctromotive forces diiiering ninety degrees in phase, the currents in the armature and field-magnet wind ings may reverse nearly simultaneously. This is true, because the current traversing the field-magnet winding may lee-largely a magnetizing or wattless current which lags nearly ninety degrees behind the electromotive force impressed upon that. circuit, While the armaturecirouit maybe and is (ordinarily made with but little self-induction, so that the current in the circuit lags but little behind the electromotive force impressed upon it. I It is obvious, then, that iftheelectromotive forces applied to the twocircuits differ ninety degrees in phase vthefchrrents in the armature and field-magnet circuits may differ but little in phase. it has been found.

in practice,'however, thatin order to'lobtain minnnum,' arfi1ture'current. for agiven torque iii-"1s necessary that the currents 1n 'the armature and field circuits 'be more nearly coincident in'phase than is the case-if" only the differences of the power factors of the [circuits are depended upon to produce the proper re ations. The msuficiency, of

workwhieh the motor is (loin,

' herewith.

the power-factor conditions of the c rcuits is partially due to the fact that the armature circuit cannot be made entirely non-mduct ive. Moreover, when constant voltages are applied to the armature and field-magnet windings the'amountofv current in the fieldmagnet winding, as well as its phase relation 'with respect to the electromotive force ap plied to the winding, remains practical constant even under variations in the lo themotor, but the amount of or armature-circuit varies a relations of this current with. electromotive force applied to the armature Winding varies as theamount of. current varies. Thus the phase relations of the currents in the armature and field-magnet windings-With respect to each pther vary as the work donehy themotor varies. With no load on the motort; ith but small currents flowing in the atature circui he phase relations may be reasonably close to 'whatisdesired; but as load is placed on respect to the motive force applied to one circuit with respect to that applied to the other in accord- I once with changes in load or. byaltering the pliaserelation of the current to the electromotive force in the; armature-winding-or 1nthe field-magnet-winding, or in both.v Only 3 the first.ofthese methodsis practiced by my invention.. 7 I

Other means and a method for effecting adjustment of the phase relations of the cur. rents in the armature and field-magnet Windings are described in an application Serial No. 244,482, filed jointly by Benjamin G. Lemme and myself, and in applications Se. rial Nos. 244,475, 244,476,, and 244,477, filed byBenjamin G.

Lemme, all of even date in acco' Ell.

My invention is illustrated in the accomying drawings, in which Figure 1 illustrates diagrammatically a two-phase source 0% energy and a motor sup:

- plied therefrom that is provided with a spe-.

oific type of phase-adjusting means. Figs. 2 and 3 are vector diagrams illustrative of the approximate; phase relations of the currents and electromotive forces or" the motor shown in Fig. 3. Figs. l, 5, and 7 are diagrammatic views illustrating modifications appliec to the armature-wmding comprising a pivoted arm 7, adapted to engage contactterminals 8, which are connected to spaced points in the transformer winding 1 by means of leads 9.

@ne: terminal or" the field-magnet winding '10 of the motor. 6 is connected to supplycon ductor. 11 nd the other terminal is connected to a suitable conducting-strip 12 of a regulatiug deyice 13. A crush 14;- isadapted to make, sl' ng contact with tie conductingstrip 12 and to engage con t-terniinals 15, which are connected to suitahlyspaced points in a winding 3.6, which is placed in the same magnetic circuit the transformer-winding 1 and one terminal of which is connected to sup .lV- -conductor 17. The brush 14 is carrice 1': the core 13 of SOl8l10lCl 19, which is the pul device-l3 is 0 means for van 1%, include.

ionsin the amount .reeircuit, and that ating this result may be employed which ll my int ention.

An understanding-of the approximate phaserelationsof the currents and electromotiye forces in the armature and field magnet windings under the different cc? may. Figs, 32 and 3. l n'Fig. 2 I have, shown the ap; climate .-circuit, substantially.

l be within the scope of.

tions from consideration or" eeaeee occur in the motor if no auxiliary devices were employed for altering them. Lines OE,, and OF represent, respectively, the electr0- motive forces applied to the armature and field-magnet windings, and lines 01,, and 0L represent in direction the currents in the armature and field-magnet windings. The angle 6 represents the phase difference between the currents in the armature and in the field-magnet windings. It will be observed that in Fig. 3 the phase of the electromotiye-torce U1} is indicated as shifted from I the relation shown in Fig. 2 with respect to the elec romotiye force GE since whena part or the whole or" the transformer-winding 16 is included in the field-circuit the electroniotive force OE which is applied to the field-magnetwinding, is the resultant of the lectromotiye force OE that is derived from the en 1 circuit and theelectromtive force SC, tha'tis derived from the winding 16, the ,electromotive force OC- being in phase with the electromotive force OE F 01; is determined by the-power factor of the field-circuit and remains the same in both cases. As above noted, the angle E OE in 3 is less than the corresponding angle in Fig. 2, and hence the angle (9 in Fig. 3 is less than the angle 9 in Fig. 2.

with the field-current, the line OL- may represent the phase direction of the field magnetisn as well as that or" the held-current.

The torque exerted by the armature of is a maximumt. a, when the field and armature currents are most nearly in phasev the power factor of the motor is a maximum.

and the armature-current a minimum for that particular torque.

It will he understood that the electronicti've force represented by theline 00 may be chosen of such magnitude that the resultant electromotive force OE and the correspond-- ing current 0L may be shifted to bring the field-magnet current 0L and the armature;

The field magnetism bemgproportional to and in phase. I

The angle It is obviousthat when 1 r c 5 is a maximum, and when the component OD current 0L into phase with each othen-i. e.. so that the lines 0L and 01, Wlll c01nc1de in direction. tion for operation'and, as just stated, maybe attained if the component forces are roperly While this is a desirable c0ndi-- By proper adjustment of theregulating device 13 it may be caused to operate so as to maint ain the phase relations of the currents phase l'QLut-lOES as they wouldv in the armature-and field circuits approxian'electric motor the-armature of which is .mately constant, regardless of variations in" the. amount, of load, given voltages applied-to the motor-windings. Various modifications of my invention, such as are shown inFigs. 4, 5, and 7, may be found of use in special cases, though'in genera] not so economical in construction. ,In Fig. 4 the winding 16 is the secondary winding of a separate transformer 21 from that which supplies energy to the armature-winding the 1primary windingv 2,2 of which is con nected etween the same supply-conductors I3 and 4 as the transformer-winding 1. The

approximate phase relations of the currents and electrom'otive forces inthe armature and geld-magnet windings of Fig. 4 are shown in In Fig. 5 the winding 16 of an autotransformer 23 is connected between'supply-conductors i' and 17 the currents of which differ in phase. The approximate phase relations are shown'in Fig. 6, in which the electromotive force OE, impressed upon the field- 'magnet winding is the resultant of the electromotive force OE applied to the field-circuit and the electromotive force OC derived" from the winding 16. Anautotransformer 24-may also be connected between the same supply-conductorsB and 4 as is the main transformer-winding '1- and the points of connection of the field-magnet winding therewith may be shifted in accordance with- J variations in the amount of current traversing/the armature-circuit, substantially as shown in Fig.- 7. While I have shown and described my in- 'vention-as employed only for the purpose of altering the phase of the current inthe field,-

' and located magnet winding with respect;to that-of the current in thetarmature-winding, it. is of course understood that if'it is desired so-to do the phase of the current in the armature-. winding with respect to that of the current in the field-magnet winding ma bead'usted in accordance with-the same method an to meet the same or any other desired conditions. i Iclaim as my invention- 1. The combination .with a source of twophase alternatingscm'rent energy, ;a transormer connected to one phase of said source,

supplied by. said-transformer, .means for con; nectingthe field-magnet to the otherv phase. of. said source, and awin'ding connected in series with the fieldsmag'net in the magnetic circuit of the transformer.

2. The combination .of a source of twohase alternating-current ener a transormer connected to one phase oi aid source, an electric motor the armature of which is supplied by said transformer, means for connectmgg-the field-magnet winding to} other hase of said source, a wlnding on necte in series with the field-magnet ly nd tive length of said windin and located in the magnetic circuit of the transformer, and means, or varying the ac- I 3. The combination of a source of two- I phase alternating-current ener y, a transormer connected to one phase 0 said source, an electric motor the armature of which is supplied by said transformer, means for connecting the fields-magnet winding to the other phase of said source, a winding connected in series with the field-magnet winding and located in the ma netic circuit of the transformer, and means for varying the active length of said Winding substantially in accordance with variations in the current traversing the armature-circuit.

4. The combination of a source of twophase. alternating-current energy, a transformer connected to one phase of said source,

an electric motor the armature of which is supplied by the transformer, means for. connecting the field-magnet Winding to 'the other phase of said source, a winding connected inseries with the field-magnet Winding and located in. the magnetic circuit of the transformer, and means for varying the active length of said Winding comprising a controlling device responsive in its operation to var ations 1n the current traversing the armature-circuit.

5. The combination of a source of twophase alternating-current energy, a transsaid source, an electric motor having armature andfield-magnet windings, meansfor connecting the armature-winding to points in the transformer-winding, means for connecting .the field-magnet winding tothe other phase of said source, and. a transormer-winding supplied from one phase of other phase of.saidsource, a transformer winding that is connected in series with the field-magnet anduponwhich is impressed an electromotive force of a different ,7

' .phase fromthat. im ressedupon the fieldmagnet an means-for varying-the active lengtho saidwinding. 7. The combination of a source of twophase alternating-current energy,-a transormer-wmdingsupplied from one phase of "said source, an electric motor having arma- *ture and field-magnet windings, means. for

' 'connecting the armature-windingto points 1 0* in the transformer-winding, means for connecting the field-magnet winding to the other phase of said source, a transformer-winding that is connected in series with the fieldmalgnet winding andupon which is impressed an electromotive force of different phase from that impressed upon the field-magnet winding, and means for varying the active length of said winding substantially in accordance with variations in. the amount of current traversing the armature-circuit.

8. The combination of a Source of 'twophase alternating-current energy, a transformer-winding supplied from one phase of said source, an electric motor having armature and field-magnet windings, means for connecting the terminals of the armature winding to points in the transformer-winding, means for connecting the field-magnet winding to the other phase of said source, a transformer-winding that is connected in series with the field-magnet winding and upon which is'impressed an electromotive force of different phase from that impressed upon the field-magnetwinding, and means for varying the active length of said winding comprising a controlling device responsive in its'opera tion to variations in theamount of current from that impressed upon the field-magnet winding.

'10. The combination with a source of twophase alternating-current energy and a transformer supplied from) one phase of said source," of an electric motor the armatureterminals of which are connected-to said transformer, means for changing the said co nnections to vary the voltage applied to the armature-winding, means for connecting the field-magnet winding to the other phase of said source, a transformer-winding that is connected in series with the field-magnet winding and upon which is impressed an electromotive force of a different phase from that impressed upon the field-magnet winding,

and means for varying the active length of said winding.

11." The combination with a source of alternating-current energy and a transformer supplied from one phase of said source, of an electric motor the armature-terminals of which are connected to said transformer,

means-for applying an'ele'ctrdmotive force of another phase to thefield magnet-winding, anda transformer-winding that is connected in series with the field-magnetWinding and is located in inductive relation to the main transformrer-Windings.

ternating-current energy and a transformer supplied from one phase of said sourceyof -an electric motor the armature 'termina-ls of which are connected to said transformer, means for applying an electromotive forceof another phase to the 'field-magnet-winding, and a transformer-winding that iscon'ne'cted in series with the field-'magnet-winding' and is located upon the same magnetizable' core as the main transformenwindings.

13. The combination with a sOurce of alternating-current energy and a-trans'iorrner located in inductive reiationfitothe' main transformenwlndings, andmean'sfor'varying the active lengthof saidwinding.

14. The combination withiaeource ol al- 1 12. The combination Wltlffii source ofal i v99 series with the held-magnet winding and 11S ternatin -current'ener" and a" transformer g eJ another phase to the field-magnet winding, a

'transf'orn'ierwindin that is connected in series with the field-ma net'wmdmg'and is located in inductivere lation to 1 the -main transimmer-windings; and'means for varying the electromotive force impressed upon' the field-circuit by the said winding.

15. ihe combination with a source of ah ternating-current energy-and a transformer supplied from one phase-of saidsou'rceyofan electric motor the arma'ture' terminals of which are connected to "said transformer, means for applyin electromotivedcrce of another'phase to the fieldanagnet-winding', a transformer-winding that is connected in series with the field-magnet winding and'is located in inductive relation to the main transformer-windings, and means for varying the electromotive force impressed upon the field-circuit by said winding-substantially inaccordance with variations in the amount of current traversing the armature-circuit.

16. The combination with a source of alternating-current energy and a motor the armature and field circuits of which are supplied with electromotive forces differing in phase, of atransformenwinding that is located in one of the Inotor-circuitsandupon which is impressed an electromotive force of a different phase from the main -electro1no tive force impressed upon that circuit, and

means for varying the active length of said winding substantially in accordance with the variations inrthe amount of current traversing the armature-circuit.

. 17. The combination with a source of alt'ernatmg-current energy, a transformer supplied from one phase of said source and a motor having armature and field magnet windings, of means for connecting one of the motor-windings to the transformer-winding and the ,othenmot'or winding to another phase of said source, and a transformer-windmg that is connected in series with one of the motor-windings and upon which is impressed 1 an electromotive force of a different phase from the main electromotive force impressed .u on that winding, and means for varying t e active length of said winding substantially in accordance with the variations in the amount of current tra ersing the armature-circuit.

In testimony whereof I have hereunto subscribed my name this 3d day of February, 1905.

CLARENCE REN SHAW.

Witnesses:

OTTO S. SGHAIRER, BIRNEY HrNEs. 

